During transmission of IP (Internet Protocol) packets carrying MPEG (Moving Picture Experts Group) payload, the need sometimes exists for discarding a portion of such IP packets. Examples of such situations include, but are not limited to, a network exhibiting congestion, facilitating fast-channel change functionality, performing various stream management functionalities, and the like. To facilitate such discarding in a manner that limits adverse impact on a quality of service (QOS) observed by a client, an IP device such as, for example, a router, switch, or DSLAM must first identify packets that can be discarded without adversely impacting such QOS.
Known approaches that exist for facilitating discarding of IP packets in an IP packet stream (i.e., packet stream traffic) exhibit one or more deficiencies. One such approach includes classifying the type of packet stream traffic using a corresponding IP TOS (Type of Service) field and a corresponding DSCP (Differentiated Services Code Point) values. Using this method, an IP device can classify “types” of packet stream traffic (e.g., voice, video, data, signalling, and so on), but has the deficiency of not being able to differentiate between the various degrees of importance of individual IP packets and contents thereof within those types. Another such approach includes performing MPEG analysis of a video stream (i.e., a packet stream known to be carrying video content) to determine its packet-specific content and, therefore, the qualitative value of such content relative to the overall video stream. This second approach has the deficiency of requiring task-specific hardware and/or software, which can significantly increase the cost and/or complexity of such an approach.
Therefore, an approach for allowing MPEG video packets of an IP packet stream to be discarded in a manner that limits adverse impact on the IP packet stream as-delivered to a recipient and that overcomes deficiencies associated with known approaches for discarding packets of packet stream traffic would be advantageous, desirable and useful.